by America’s Master Handyman, Glenn Haege

Until about twenty years ago, very few people even knew about air duct cleaning. Now it’s a growth industry. My friend, Mike Palazzolo, at Safety King, also runs a duct cleaning school and is getting inquiries from as far away as Malaysia.

The reasons for the sudden interest are that houses are getting tighter, increasing the prevalence of indoor air pollution, and consumers are getting smarter.

Inside air is far more polluted than outside air. Efforts to lower energy consumption through tight construction and energy efficient HVAC systems, often create concentrations of pollutants ten to 100 times greater than that found out doors. That’s one of the reasons why I demand that higher air quality standards be built into new energy codes. I don’t care how well insulated your house is, if you can’t breath, you can’t listen to my radio shows or read my columns.

Most people spend about 90 percent of their time indoors. About half of that time is in our own homes. Infants and elderly people send virtually 100 percent of their time in their homes. The quality of the air we breath at home is a matter of life and death importance.

Stachybotrys, a nasty little member of the mold family, can be found in about 5 percent of American homes. Generally it is in homes with a chronic moisture problem, i.e. where drywall or ceiling tile has been damp for an extended period. The mold breeds in the wet cellulose, then gets into the duct work and spreads through the air.

Connie Morbach of Sanit-Air, showed me research reported in the October ’95 issue of Indoor Air Quality Update, linking Stachybotrys with neurological disorders, such as memory loss and sleeplessness in adults and death in infants. A recent study in Cleveland linked it with 11 infant deaths.

Aspergillis, another member of the mold family spread through dirty ductwork, is related to chronic infection in the respiratory system. There are also dust, dust mites, human and pet hair, and various other forms of allergens, that often accumulate as an up to 15 pound, 2-inch thick layer of debris lining the air ducts in many houses.

To find out if you need to have your ductwork cleaned Morbach suggests taking off a cold air return register to see how much debris has collected. If it looks dirty, go to the furnace room and bang on the air return duct work.

If you hear rattling, that is chunks of concrete and drywall, nails, etc., the duct work should be cleaned. If it sounds like a dull thud, it means debris is lining the ducts, and needs to be cleaned out. If you hear a hollow booming sound, the duct work is clean.

Not all cleaning is equal. Some firms just open the registers and clean a short way into each opening. Other firms vacuum, then spray a petroleum based concoction into the ducts to immobilize the rest of the crud.

The only form of duct cleaning I recommend is Source Removal. Firms using this technique usually use truck mounted vacuums that generate 20,000 cubic feet per minute of cleaning power. They go to the furnace area, cut holes in both the cold air return and heating ducts, and clean the entire length of the duct work, then clean the furnace.

If you decide that your home’s duct work should be cleaned the next decision is whether it should be sanitized. If your family suffers from chronic flu-like symptoms: headaches, runny noses, malaise, difficulty breathing, or suffer from allergies, sinus, or bronchial conditions there is a good chance that the duct work should be sanitized.

Your home is also a good candidate for sanitization if it has undergone remodeling, flooding, or fire; or if there are unusual or unpleasant odors. There are two primary methods of sanitizing duct work: chemical and the ozone. Both work. I’ll write more about duct sanitizing in my next column.

When looking for a duct cleaning company, check out its bragging rights. Make sure they use source removal techniques. Mike Palazzolo (the friend with the duct cleaning school) has a list almost 60 companies that do duct cleaning in this area, but there are only 12 companies in Michigan with certified duct cleaners according to the National Air Duct Cleaners Association in Washington, DC. If you’d like a recommendation from the association, call (202-737-2926).

Sanit-Air (888-778-7324) is a duct cleaning company that also does indoor air quality assessments, and specializes in the ozone method of sanitizing. They have a certified ozone technologist on staff and are members of the International Ozone Association. Safety King (800-972-6343) is one of the oldest specialized companies in the business. A-1 Duct Cleaning (800-382-8256), Dalton Environmental (800-675-2298), and Sterling Environmental (888-992-1200) are other companies that specialize in duct cleaning. Flame Furnace (313-527-1700) and Bergstrom Heating & Plumbing (313-522-1350) are heating contractors that also do duct cleaning.